Cell theory meets the definition of a scientific theory because it can be proven, it has been tested for a long period of time and therefore there are many evidences that support the theory but not enough to become a law. Well scientific laws are statements based on repeated experiments or observation, but also, a law is something that always applies under the same conditions. Evolution occurs in the characteristics of living things within a species overtime. . A theory is much more complex: it explains why something happens. A law only describes what happens.
The cell theory meets the definition of a scientific theory but i do not think it should be a scientific law.
This is an example of Newton's second law that says that you will need more force to move an object of a lot of mass. F = m×a; F=Force= M= Mass×A= Acceleration